The present invention relates to the field of pump building, and more particularly, to hydraulic drive pulsators of reciprocating action.
The invention is mostly applicable to the production of diaphragm pumps with a hydraulic drive of the diaphragm and of hydraulic drives for obtaining precise reciprocating movements.
As is known to those skilled in the art, there are hydraulic drive pulsators of reciprocating action. For example, use is made of pulsators of reciprocating action for diaphragm hydraulic drives in the diaphragm pumps.
The pulsators of known designs comprise a housing with a cavity filled with liquid and communicating with the cavity of the cylinder adjacent to the housing located wherein is a spring-loaded piston set in reciprocating motion by an eccentric fastened to the driving shaft of the pulsator located in the cavity of the housing, with the cylinder cavity under the piston being hydraulically connected to the chamber of the actuating mechanism incorporating a device compensating for the liquid leakage therefrom and protecting it against pressure overloads.
In known pulsators the system for maintaining a constant amount of liquid and its pressure in the chamber of the actuating mechanism consists of two spring-loaded valves, viz. a filling or a relief valve and a safety valve. These valves actuate when acted upon by a certain pressure differential. The value of the pressure differential is established by adjusting their springs. This operation requires highly-skilled personnel and it is difficult to be performed under service conditions.
Besides. no valves are absolutely liquid-tight, i.e. they allow for some amount of liquid to leak, therefore, any of the mentioned valves is a source of varying the constant amount of liquid in the chamber of the actuating mechanism, thus reducing the efficiency and the reliability of the pulsator operation, as well as the accuracy in maintaining the preset pulsating consumption of liquid.
The object of the present invention is to overcome the mentioned disadvantages and to provide a more reliable and efficient design of a reciprocating hydraulic drive pulsator.